1841.] Succinct Review of the Observations of the Tides, fyc. 303 



Also on the Coriman Islands, from the 18th July 1838 to April 

 1839, by deputy of the civil service, Michalosske. 



These two latter observations were forwarded by the favour of the 

 Batavian Society of Arts and Sciences, which had already previously 

 made (at the request of Prof. Whewell, Trinity College, Cambridge) 

 some communications with regard to the tides in this Archipelago, to 

 the Asiatic Society in Calcutta ; besides these, there were some obser- 

 vations made at Macassar in the year 1840, by the master in the navy, 

 E. Lagto, after they had been finished at the other stations. 



These observations furnish the following results concerning the 

 respective stations : — 



At Pulo Chinco off Fjinks, West coast of Sumatra. The course of 

 the flood tide and the rise of the water on the coast was observed 

 to run from N. E. to S. W., closely following the direction of the coast. 



The ebb tide ran in the opposite direction, and though both tides 

 were very trifling, not exceeding a quarter of a mile, yet the force of the 

 ebb generally exceeded that of the flood, though neither were sensibly 

 influenced by the wind. 



The tides were, however, very regular. The mean duration was 

 about six hours and a quarter, so that as usual, there were two tides 

 in a day. 



At new and full moon the high water was generally between 5h. 30m. 

 and 6h. 30m. viz. At new moon. a. m. at 6h. 24m. 



p. m. at 6 30 

 At full moon. a. m. at 5 28 

 p. m. at 5 35 

 average time about 6 — 00, and the time of flood tide during the 

 other days, followed the common rule, dependant upon the moon's 

 passing the meridian, according to which, though not always with the 

 same regularity the tide came in every day generally about three 

 quarters of an hour later, or rather in the course of a fortnight the 

 variation amounted to twelve hours. If then six hours be supposed as 

 mean number, it was almost always flood tide when the moon was 

 in the horizon. 



From the time of high water to the time when it again turns to ebb, 

 as is here noticed, we may be allowed to fix 5h. 30m. as the mean 

 number. 



